不同海拔垂穗披碱草种子产量及其构成因素

Seed yield and seed yield components of Elymus nutans from different elevations

在甘肃榆中地区同一生境下,研究了采自甘南不同海拔高度(2 500、3 000、3 500和4 000m)垂穗披碱草(Elymus nutans)种植第2年的种子产量及其构成因素。结果表明,4个种群内的变异系数均为单株种子产量、单株干重和单株生殖枝数较大,表明种群内选择育种的潜力大,其次是千粒重和收获指数,每生殖枝小穗数与每小穗种子数的变异系数最小。海拔对种子产量及其构成因素也有显著影响,表现为海拔4 000m种群单株种子产量显著低于其它种群(P<0.05),为14.58g·株-1,海拔3 500m种群单株种子产量最高,为23.77g·株-1,但与海拔3 000和2 500m没有显著差异。4个海拔的种子产量与其构成因素的相关性不完全一致,除千粒重、每生殖枝小穗数和收获指数外,各因素与产量间均为正相关或显著正相关,相关系数表现为单株干重>每株生殖枝数>每小穗种子数。

Seed yield and yield components of Elymus nutans introduced from different elevations which were 2 500, 3 000, 3 500, 4 000 m were evaluated. The results indicated that seed yield per plant, dry weight per plant and fertile tiller number per plant attained relative higher coefficient of variation（CV）, and harvest index, spikelet number per fertile tiller and seed number per spikelet had relative lower CV. There were significant difference among populations from 4 elevations in terms of seed yield and its components （P〈0.05）.The population from 4 000 m elevation attained significantly lower seed yield per plant （14.58 g·plant-1） than the other populations. The highest seed yield per plant was 23.77 g·plant-1 which attained at the population from 3 500 m, but showed no difference with population from 3 000 m, 2 500 m. Except thousand seed weight, spikelet number per fertile tiller and harvest index, there were positive correlation or significant positive correlation between seed yield and the other yield components, the correlation coefficient can rank as dry weight per plant〉fertile tiller number per plant〉seed number per spikelet.